Insulating end post



April 4, 1967 x.w. CRUIKSHANK `INSULATING END POST Filed April so, 1965 FIG. 3

INVENTOR. JOHN W. CRUIKSHANK j 'ATT'ORNEY United States Patent O 3,312,399 INSULATING END POST John W. Cruikshank, Northbrook, Ill., assignor to The Goodyear Tire 8: Rubber Company, Akron, Ghio, a corporation of Ohio Filed Apr. 30, 1965, Ser. No. 452,319 4 Claims. (Cl. 23S-152) This invention relates to end posts for use between the meeting ends of railway rails to insulate one rail from another in conjunction with insulated raily joints employed in block signal systems.

Heretofore most railroad end posts have been made of liber. End posts of this type are very susceptible to moisture and once exposed to weather tend to delaminate vertically. This gives rain and other moisture a perfect passage to the base piece and even acts as a reservoir for holding moisture. Other materials such as rubber or plastic have also been used in the construction of end posts. However, these materials have not been satisfactory since they do not adequately resist abrasion, the crushing force of the train wheels passing over V`them and the pressure caused by expansion of the rail due to temperature changes. These previously used materials are also subjected to deterioration caused by oil dripping from passing trains.

An object of this invention is to overcome the foregoing diiculties by providing an end post which is resistant to crushing, tearing and abrasion caused by railroad cars passing over it.

Another object of this invention is the provision of an end post which is resistant to moisture, oil, solvents and u1traviolet rays.

Another object of the invention is to combine the resilient characteristics of an elastomeric material with the stiffness and abrasion resistance of a metal to form an end post which -is durable, simple to manufacture and is highly reliable as an electrical insulator between rail ends.

A still further object of this invention is the provision of an end post having molded-in-place inserts which transmit stress between the core material and the rail ends and prevent friction damage to the end post by the rail ends.

Still another object of this invention is to provide an end post in which the material recovers quickly from the crushing pressure of the wheels and which tends to push out metal particles which sometimes lodge between the rail ends and cause shorting out of the signal system.

These and other objects of the invention will become apparent in the following specifications and attached drawings in which FIG. 1 is a vertical elevation of the improved end post,

FIG. 2 is a side elevation of the end post shown in FIG. 1 with a portion broken away to show the structure; and

FIG. 3 -is a cross-sectional view along 3-3 of FIG. 1.

Referring more specifically to the drawings, the end post designated generally by the numberal 1 is a sandwich-type construction which has an elastomeric core 2 and a face sheet 3 on each side of the core 2 to provide vertical stiffness and protect the core 2 from abrasion by the rail ends. The core 2 is preferably made of a polyurethane which is the reaction product of a polyester, an organic diisocyanate and a diamine as described in U.S. Patent 3,107,235 and sold under the trademark Neothane, a trademark ,of The Goodyear Tire & Rubber Company. It will be understood, however, that other elastomeric materials which have the required physical properties can also be used for the core 2. The face sheets 3 are preferably made of steel. However, other materiials which will provide adequate stiffness to the end post 1 and protect it from abrasion may also be used.

ICC

The end post 1 has a prole conforming with the crosssectional shape of the ends of the rails with which it is to be used and like most conventional rails has a head section 4 on the top, a flanged base S on the bottom and a web 6 connecting the head 4 and the base 5.

In the drawings it will be observed that the face sheets 3 have the same peripheral dimensions as the core 2 in the base 5 and the lower portion of the web 6 but have smaller peripheral dimensions than the core 2 around the edge of the head 4 and approximately the upper half of the web 6 so that in this part of the end post the edges of the face sheets 3, when positioned on the core 2, lay laterally inwardly from the edge of the elastomeric core 2. This means that the edges of the face sheets also lay laterally inwardly from the top and sides of the rail heads which abut the end post and therefore will not be subjected to the crushing force and wear of the train wheels passing over the track. Only the elastomeric core 2 will be in Contact with the train Wheels and it will, of course, yield to the pressure of the wheels and spr-ing back after each wheel has passed over it. In so doing, it will tend to push out metal particles which might otherwise collect in the spaces between the ends of the rails and short out the track circuits.

If the core 2 were completely flat, a gap Would be left between the core 2 and the face sheets 3 around the edge of the end post in the area where the face sheets are smaller than the core. Such open space would trap moisture and various foreign particles and would tend to cause separation of the face sheets 3 from the core 2. To avoid such a gap an integral lip 7, perpendicular to the face of the core 2, extends outwardly from each face of the core 2 the same distance as the thickness of the face sheet and lls in the space left by the smaller dimension around the ends of the face sheets 3. The lips 7 also help to retain the face sheets 3 in position on the core 2 and aid in maintaining the bond between the face sheets 3 and the core 2.

This end post may be made by casting in place the core material between the face sheets 3. If Neothane or certain other polyurethane compounds are used, they will adhere to the metal face sheets without'the need for additional bonding material. The face sheets and core may also be made separately and bonded together with some suitable adhesive. However, where the core 2 is cast in place, no stresses are created between the core 2 and the face plates 3 as might be if the core and face plates were made separately and bonded together afterwards. For this reason the cast-in-place core gives a superior bond which is less likely to result in separation of the face sheets 3 from the core 2 than when the core is made separately from the face sheets.

It will be seen that this sandwich-type and post structure combines the resilient characteristics of an elastomeric material with the stiffness and abrasion resistance of metal and provides an elastomeric core which will be resistant to crushing by the train wheels, and unlike ber end posts, will not delaminate and permit moisture to penetrate and cause further deteroration thereof. Due to the composition of the material from which the core is made, it will resist solvents, oil and ultraviolet rays. This is particularly true when the core is made of Neothane. The core is also abrasion and tear resistant and these qualities are further enhanced by the protective metal face sheets which stiffen the core and protect it from the abrasion against the rail ends. The face sheets are in such a position in the rail joint that they remain free of contact with the rail wheels and therefore are not damaged thereby.

While certain representative embodiments and details have been shown for the purpose of illustrating this invention, it will be apparent to those skilled in the art that Various changes and modifications may be made therein without departing from the spirit or scope of the invention.

What is claimed is: 1. A n insulating end post to be placed between meeting rail ends at a rail joint comprising (A) A non-conductive elastomeric core having a head portion, a web portion and a base portion, formed to the profile of a given rail section, said core having on both sides thereof an integral lip along at least a portion of the edge of the core, said lips being substantially perpendicular to the face of the core, and (B) A pair of substantially identical metal face plates attached to each face of the core, said plates being of the same general contour as the core but having that portion of their edge removed which corresponds to the position of the lips on the core so that when both face sheets are positioned against each face of the core the lips enclose a portion of the edge of each face sheet and help to retain the face sheets in proper alignment on the core. 2. An end post as claimed in claim 1 wherein the integral lip extends around the edge of the head portion and approximately half way down each edge of the web portion and the thickness of the lip is the same as the thickness of the face sheets so that when the face sheets are at against the faces of the core the outer surface of the lips are level with the outer surface of the face sheets.

3. An end post as claimed in claim 2 wherein the core is formed from a polyurethane compound.

4. An end post as claimed in claim 3 said polyurethane being the reaction product of a polyester, an organic diisocyanate and a diamine.

References Cited by the Examiner FOREIGN PATENTS 3/ 1955 Great Britain. 12/ 1962 Great Britain. 

1. AN INSULATING END POST TO BE PLACED BETWEEN MEETING RAIL ENDS AT A RAIL JOINT COMPRISING (A) A NON-CONDUCTIVE ELASTOMERIC CORE HAVING A HEAD PORTION, A WEB PORTION AND A BASE PORTION, FORMED TO THE PROFILE OF A GIVEN RAIL SECTION, SAID CORE HAVING ON BOTH SIDES THEREOF AN INTEGRAL LIP ALONG AT LEAST A PORTION OF THE EDGE OF THE CORE, SAID LIPS BEING SUBSTANTIALLY PERPENDICULAR TO THE FACE OF THE CORE, AND (B) A PAIR OF SUBSTANTIALLY IDENTICAL METAL FACE PLATES ATTACHED TO EACH FACE OF THE CORE, SAID PLATES BEING OF THE SAME GENERAL CONTOUR AS THE CORE BUT HAVING THAT PORTION OF THEIR EDGE REMOVED WHICH CORRESPONDS TO THE POSITION OF THE LIPS ON THE CORE SO THAT WHEN BOTH FACE SHEETS ARE POSITIONED AGAINST EACH FACE OF THE CORE THE LIPS ENCLOSE A PORTION OF THE EDGE OF EACH FACE SHEET AND HELP TO RETAIN THE FACE SHEETS IN PROPER ALIGNMENT ON THE CORE. 